<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED DECEMBER 8, 1997,
TO THE CLASS C PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT CONTAINED IN
THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH SUCH
PROSPECTUS.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime
Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
Effective March 23, 1998, the NAV for the Government Portfolio, the Money Market
Portfolio and the Treasury Portfolio will be calculated in accordance with the
following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Treasury 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Government 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Money Market 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
</TABLE>
In accordance with these changes, the cutoff time for receipt by the Portfolios
of purchase and redemption orders is the time of the calculation of NAV set
forth above for each Portfolio. These changes shall become effective on December
8, 1997, for the Prime Obligation and Treasury II Portfolios, and on March 23,
1998, for the Treasury, Government and Money Market Portfolios.
The prospectus is hereby amended to reflect these changes.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED DECEMBER 8, 1997, TO THE
CLASS A AND CLASS B PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT CONTAINED IN
THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH SUCH
PROSPECTUS.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime
Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
Effective March 23, 1998, the NAV for the Government Portfolio, the Money Market
Portfolio and the Treasury Portfolio will be calculated in accordance with the
following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Treasury 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Government 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Money Market 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
</TABLE>
In accordance with these changes, the cutoff time for receipt by the Portfolios
of purchase and redemption orders is the time of the calculation of NAV set
forth above for each Portfolio. These changes shall become effective on December
8, 1997, for the Prime Obligation and Treasury II Portfolios, and on March 23,
1998, for the Treasury, Government and Money Market Portfolios.
The prospectus is hereby amended to reflect these changes.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
<PAGE>
SEI DAILY INCOME TRUST
GOVERNMENT PORTFOLIO
MONEY MARKET PORTFOLIO
PRIME OBLIGATION PORTFOLIO
TREASURY PORTFOLIO
TREASURY II PORTFOLIO
SUPPLEMENT DATED DECEMBER 8, 1997, TO THE
SWEEP CLASS PROSPECTUS DATED MAY 31, 1997.
THIS SUPPLEMENT PROVIDES NEW AND ADDITIONAL INFORMATION BEYOND THAT CONTAINED IN
THE PROSPECTUS. IT SHOULD BE RETAINED AND READ IN CONJUNCTION WITH SUCH
PROSPECTUS.
Effective December 8, 1997, the net asset value per share ("NAV") for the Prime
Obligation Portfolio and the Treasury II Portfolio will be calculated in
accordance with the following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Prime
Obligation 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Treasury II 2:00 p.m., Eastern Time 2:30 p.m., Eastern Time
</TABLE>
Effective March 23, 1998, the NAV for the Government Portfolio, the Money Market
Portfolio and the Treasury Portfolio will be calculated in accordance with the
following schedule:
<TABLE>
<CAPTION>
PORTFOLIO CURRENT TIME TO CALCULATE THE NAV NEW TIME TO CALCULATE THE NAV
<S> <C> <C>
Treasury 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Government 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
Money Market 4:30 p.m., Eastern Time 5:00 p.m., Eastern Time
</TABLE>
In accordance with these changes, the cutoff time for receipt by the Portfolios
of purchase and redemption orders is the time of the calculation of NAV set
forth above for each Portfolio. These changes shall become effective on December
8, 1997, for the Prime Obligation and Treasury II Portfolios, and on March 23,
1998, for the Treasury, Government and Money Market Portfolios.
The prospectus is hereby amended to reflect these changes.
PLEASE RETAIN THIS SUPPLEMENT FOR FUTURE REFERENCE.
